Yoga is the best way to rejuvenate your body, and you will find hundreds of asana in Yoga. Depending the type of benefit, you are looking at; you will get asanas for each one of them. If you want to reduce weight, you can find Suryanamaskar, Dhanurasana highly beneficial to you. Similarly for the lung problem, you can try ardhackra asana. Veerbhadra as is helpful in reducing fat from your body. Whatever asana you select, you should work for a couple of minutes to start with, and later you can enhance the time.